1. Use sweet potato flour for hot and sour noodles. If it is dry, it is best to soak it in cold water overnight in advance, which can reduce the subsequent blanching time. The soybeans are also soaked overnight.

2. Put minced ginger, minced garlic, vinegar, light soy sauce, Sichuan pepper powder, pepper powder and a small piece of lard in the bottom of the bowl. Blanch the sweet potato vermicelli in boiling water until soft, put it into a bowl, pour a ladle of boiling broth over it, add red oil, green onions, coriander, parsley and pickled mustard particles, kohlrabi particles according to taste, and finally sprinkle with crispy soybeans.

3. How to make crispy soybeans: soak the soybeans overnight, drain, add a pinch of baking soda to the water, add the soaked soybeans and soak for ten minutes, submerge the soybeans in cold oil, and soak over medium-low heat Fry until crispy, drain and set aside.